We propose to study magnetic excitations in the double perovskite 3d-5d system La2CuIrO6 using IN4 time-of-flight spectrometer. Our specific aim is to establish the presence of spin gap and to estimate the magnon band width on a 5 g powder sample of this material.The crystal structure is determined by two interpenetrating fcc lattices of octahedra centred around copper and iridium ions. Previous characterisation reveals AFM phase transition at 74 K followed by FM transition at 55 K, resulting in a complex non-collinear low-temperature magnetic structure.